Natural and anthropogenic sources of habitat variation influence exploration behaviour, stress response, and brain morphology in a coastal fish

1. Evolutionary ecology aims to better understand how ecologically important traits respond to environmental heterogeneity. Environments vary both naturally and as a result of human activities, and investigations that simultaneously consider how natural and human-induced environmental variation affect diverse trait types grow increasingly important as human activities drive species endangerment.

2. Here, we examine how habitat fragmentation and structural habitat complexity, affect disparate trait types in Bahamas mosquitofish (Gambusia hubbsi) inhabiting tidal creeks. We tested a priori predictions for how these factors might influence exploratory behaviour, stress reactivity, and brain anatomy.

3. We examined approximately 350 adult Bahamas mosquitofish from seven tidal creek populations across Andros Island, The Bahamas that varied in both human-caused fragmentation (three fragmented, four unfragmented) and natural habitat complexity (e.g. 5-fold variation in rock habitat).

...